Question

The area is 30 square centimeters and a height with 10 centimeters. What is the length of the base?

Answer 1

30/10=3 3 cm is the length.

Answer 2

So,

The formula for the area of a rectangle is:
A = l * w

We will consider l to be the height.

Substitute the given values.
30 = 10 * w or 10w

Divide both sides by 10.
3 = w

The length (I would call it the width, since it is shorter) of the rectangle is 3 centimeters.